Definition

"Dentigerous cyst can be defined as an odontogenic cyst that surrounds the crown of an impacted tooth; caused by fluid accumulation between the reduced enamel epithelium and the enamel surface, resulting in a cyst in which the crown is located within the lumen"

Dentigerous Cyst:-

OTHER NAME – Follicular cyst:-

Clinical Features

• Associated with crown of an impacted, embedded or unerupted tooth
• Sometimes involve complex compound odontoma or a supernumerary tooth
• SITE – Common sites –
• MANDIBULAR THIRD MOLAR
• MAXILLARY CANINE
• MAXILLARY THIRD MOLAR
• MANDIBULAR SECOND PREMOLAR
• (since these are the most commonly impacted teeth)
• AGE – Most lesions present in second and third decades
• SEX – Male predilection
• Mostly solitary
• Bilateral and multiple cysts – usually found in association with some syndromes – Example – CLEIDOCRANIAL DYSPLASIA, MAROTEAUX–LAMY SYNDROME
• Dentigerous cysts may grow to a large size before diagnosed. Most discovered on radiographs when these are taken because a tooth has failed to erupt/ a missing tooth/ teeth are tilted/malalignment
• Occasionally painful, particularly if infected
• Potentially capable of becoming an aggressive lesion causing:-
• Expansion of bone with subsequent facial asymmetry
• Extreme displacement of teeth
• Severe root resorption of adjacent teeth
• Pain
• Cystic involvement of an unerupted mandibular third molar may result in ‘hollowing-out’ of the entire ramus with displacement of the third molar to such an extent that it sometimes comes to lie compressed against the inferior border of the mandible

Three Radiological Variations

• Central variety – the crown is enveloped symmetrically. In these instances, pressure is applied to the crown of the tooth and may push it away from its direction of eruption. May push mandibular third at lower border of mandible or in the ascending ramus and a maxillary canine into maxillary sinus as far as the floor of the orbit
• Lateral type – radiographic appearance results from dilatation of the follicle on one aspect of the crown. Commonly seen when an impacted mandibular third molar is partially erupted so that its superior aspect is exposed
• Circumferential type – follicle expands in a manner in which the entire tooth appears to be enveloped by cyst

Histopathologic Features

• Not characteristic microscopic features dentigerous cyst
• Usually shows a:-
  • Thin fibrous cyst wall derived from dental follicle, consists of young fibroblasts widely separated by stroma and ground substance
  • Epithelial lining, which is in fact reduced enamel epithelium, consists of 2–4 cell layers of flat or cuboidal cells (a thin layer of stratified squamous epithelium lining the lumen)
  • Characteristically, the epithelial lining is not keratinized
  • Rete peg formation is generally absent except secondarily infected
  • Connective tissue wall – of both normal dental follicles and dentigerous cysts is the presence of varying numbers of islands of odontogenic epithelium (sometimes sparse & inactive, while at other times in sufficient numbers)
  • Inflammatory cell infiltration of capsule common
  • Cysts which exhibit inflammation, may show presence of Rushton bodies within the lining epithelium. These are peculiar linear, often curved, hyaline bodies unknown origin (probably of hematogenous origin)
  • Content of cyst lumen – Usually thin, watery yellow fluid, occasionally blood tinged.
  • Intense inflammatory infiltrate in the adjacent capsule may lead to discontinuities in the epithelial
  • In some cysts, part of the epithelial lining may contain mucus-producing cells (result from metaplasia)

Dentigerous Cyst Oral Pathology Diagram

Treatment:-

• Depends on size of lesion
• Smaller cysts – Enucleation, Surgically removed in their entirety
• Larger cysts – Marsupialization
• Recurrence – Relatively uncommon

Potential Complications:-

• AMELOBLASTOMA - From lining epithelium or from rests of odontogenic epithelium in the wall of the cyst
• EPIDERMOID CARCINOMA
• MUCOEPIDERMOID CARCINOMA – From the lining epithelium of the dentigerous cyst which contains mucus secreting cells, or at least cells with this potential (common in dentigerous cyst with impacted mandibular third molars)